This PDF file contains the front matter associated with SPIE Proceedings Volume 10697 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

This work presents a spectral matching algorithm of missile plume detection that based on neural network. The radiation value of the characteristic spectrum of the missile tail flame is taken as the input of the network. The network’s structure including the number of nodes and layers is determined according to the number of characteristic spectral bands and missile types. We can get the network weight matrixes and threshold vectors through training the network using training samples, and we can determine the performance of the network through testing the network using the test samples. A small amount of data cause the network has the advantages of simple structure and practicality. Network structure composed of weight matrix and threshold vector can complete task of spectrum matching without large database support. Network can achieve real-time requirements with a small quantity of data. Experiment results show that the algorithm has the ability to match the precise spectrum and strong robustness.

The InGaAs Short-wave infrared detector is a temperature-sensitive device. Accurate temperature control can effectively reduce the background signal and improve detection accuracy, detection sensitivity, and the SNR of the detection system. Firstly, the relationship between temperature and detection background, NEP is analyzed, the principle of TEC and formula between cooling power, cooling current and hot-cold interface temperature difference are introduced. Then, the high precision constant current drive circuit based on triode voltage control current, and an incremental algorithm model based on deviation tracking compensation and PID control are proposed, which effectively suppresses the temperature overshoot, overcomes the temperature inertia, and has strong robustness. Finally, the detector and temperature control system are tested. Results show that: the lower of detector temperature, the smaller the temperature fluctuation, the higher the detection accuracy and the detection sensitivity. The temperature control system achieves the high temperature control with the temperature control rate is 7~8°C/min and the temperature fluctuation is better than ±0. 04°C.

To improve the spatial resolution of X-ray imaging systems, optical micro-scanning technology was taken into the existing system and the optical micro-scanning X-ray imaging systems is obtained. We can get a low-resolution X-ray image sequence by this system and then reconstruct high-resolution X-ray image. The inaccurate estimates of registration parameters, the inaccurate estimates of the point spread function and the additive Gaussian noise in the lowresolution (LR) image sequence will result in different noise level for each frame and influence the effects of reconstruction. This paper proposed an image super-resolution algorithm for different error levels Per frame, the LR frames are adaptively weighted according to their reliability and the regularization parameter. And then we complete the super-resolution reconstruction. The simulation and experiment results shows the effectiveness of the proposed algorithm.

With the frequency of the space camera become higher than before, the power noise of the imaging electronic system become the important factor. Much more power noise would disturb the transmissions signal, and even influence the image sharpness and system noise. “Target impedance method” is one of the traditional design method of P/G network (power and ground network), which is shorted of transient power noise analysis and often made “over design”. In this paper, a new design method of P/G network is provided which simulated by PI/SI co-simulation. The transient power noise can be simulated and then applied in the design of noise reduction, thus effectively controlling the change of the noise in the P/G network. The method can efficiently control the number of adding decoupling capacitor, and is very efficient and feasible to keep the power integrity.

To get high precision attitude for space telescope, a double marginal FOV (field of view) FGS (Fine Guide Sensor) is proposed. It is composed of two large area APS CMOS sensors and both share the same lens in main light of sight. More star vectors can be get by two FGS and be used for high precision attitude determination. To improve star identification speed, the vector cross product in inter-star angles for small marginal FOV different from traditional way is elaborated and parallel processing method is applied to pyramid algorithm. The star vectors from two sensors are then used to attitude fusion with traditional QUEST algorithm. The simulation results show that the system can get high accuracy three axis attitudes and the scheme is feasibility.

Pantoea agglomerans (Pan), Staphylococcus aureus (Sta), Bacillus globigii (BG) and Escherichia coli (EH), these four kinds of bioagents simulants of were cultured and then their growth curves were measured, the generation time was 0.99h, 0.835h, 1.07h and 1.909h, respectively. A small short range fluorescence lidar working at wavelengths of 266nm and 355nm was designed and used to measure the two-dimensional fluorescence spectra of bioagents simulants in the amino acid segment and NADH segment, respectively. In a controllable fluorescence measurement chamber, the two-dimensional fluorescence spectra of vegetative liquid bacterial aerosols as well as BSA and OVA, two protein toxinic simulants were measured with a resolution of 4nm. The two-dimensional fluorescence spectral shape of Pan, Sta, EH and BG, BSA and OVA were consistent with the standard fluorescent component tryptophan in the amino acid band with FWHM of 60nm, but the central wavelength of the fluorescence spectra of these simulants blue/purple shifted obviously as affected by the external biochemical environment, concentration and ratio of different bacterial internal fluorophores, so the energy level between the excited state and the ground state of the fluorescence molecule increased. Differently, weak NADH fluorescence spectra with 100nm FWHM inside the four vegetative bacteria aerosols were detected, but Rayleigh scattering, Raman scattering contribution of water, nitrogen in the fluorescence spectra could not be effectively extracted. The second - order derivative fluorescence spectra of four simulants showed that the high - order processing and recognition of the fluorescence spectra was feasible.

When SUSAN filter is used to model the infrared image, the Gaussian filter lacks the ability of direction filtering. After filtering, the edge information of the image cannot be preserved well, so that there are a lot of edge singular points in the difference graph, increase the difficulties of target detection. To solve the above problems, the anisotropy algorithm is introduced in this paper, and the anisotropic Gauss filter is used instead of the Gauss filter in the SUSAN filter operator. Firstly, using anisotropic gradient operator to calculate a point of image's horizontal and vertical gradient, to determine the long axis direction of the filter; Secondly, use the local area of the point and the neighborhood smoothness to calculate the filter length and short axis variance; And then calculate the first-order norm of the difference between the local area of the point's gray-scale and mean, to determine the threshold of the SUSAN filter; Finally, the built SUSAN filter is used to convolution the image to obtain the background image, at the same time, the difference between the background image and the original image is obtained. The experimental results show that the background modeling effect of infrared image is evaluated by Mean Squared Error (MSE), Structural Similarity (SSIM) and local Signal-to-noise Ratio Gain (GSNR). Compared with the traditional filtering algorithm, the improved SUSAN filter has achieved better background modeling effect, which can effectively preserve the edge information in the image, and the dim small target is effectively enhanced in the difference graph, which greatly reduces the false alarm rate of the image.

In this paper, a method for measuring the non-uniform refractive index field based on the light field imaging technique is proposed. First, the light field camera is used to collect the four-dimensional light field data, and then the light field data is decoded according to the light field imaging principle to obtain image sequences with different acquisition angles of the refractive index field. Subsequently PIV (Particle Image Velocimetry) technique is used to extract ray offset of each image. Finally, the distribution of non-uniform refractive index field can be calculated by inversing the deflection of light rays. Compared with traditional optical methods which require multiple optical detectors from multiple angles to synchronously collect data, the method proposed in this paper only needs a light field camera and shoot once. The effectiveness of the method has been verified by the experiment which quantitatively measures the distribution of the refractive index field above the flame of the alcohol lamp.

Owing to the limitation of optoelectric imaging systems’ pupil, it is inevitable to generate the diffraction effect in laser propagation; however, the laser energy distribution causing by the diffraction effect can directly affect the jamming effect to optoelectric imaging systems. First of all, we began with the basal Huygens-Fresnel principle and Fresnel-Kirchhoff diffraction formula in this paper, and deduced the laser energy distribution formula on the optoelectric imaging systems’ detector causing by the rectangular pupil, circular pupil and annulus pupil. Secondly, we simulated the laser energy distribution causing by the diffraction effect under the different pupil shapes, laser launch parameters, optical system’s parameters and optoelectric detector’s parameters, and investigated the laser energy distribution rule under the different conditions. The simulation results indicated that the range of intensity distribution increased with laser wavelength, laser incident energy, focal length and the size of pupil that also can affect the pattern of intensity distribution. The research fruits can provide the theoretical basis and technical support for evaluating laser jamming effect to optoelectric imaging systems.

In this paper, a simulation system based on commercial projector is proposed to test the optical navigation algorithms for autonomous planetary landing in laboratorial scenarios. The design work of optics, mechanics and synchronization control are carried out. Furthermore, the whole simulation system is set up and tested. Through the calibration of the system, two main problems, synchronization between the projector and CCD and pixel-level shifting caused by the low repeatability of DMD used in the projector, are settled. The experimental result shows that the RMS errors of pitch, yaw and roll angles are 0.78’, 0.48’, and 2.95’ compared with the theoretical calculation, which can fulfill the requirement of experimental simulation for planetary landing in laboratory.

This paper studies the observability analysis of multi-station orbit estimation system and provides a modified observable degree algorithm based on condition numbers. First, satellite’s status equation and measurement equation are established and discreted. Then the state transition matrix and the observation matrix are given to calculate the observable matrix. Final, plug station coordinates into the observable matrix and the modified analysis method is been applied to verify that the condition numbers parallel the orbit determination error. The simulation results proved the effectiveness of the modified method.

We proposed a saliency based algorithm to detect the ground mobile targets, such as plane and vehicle, in the images. The algorithm combines the bottom-up and top-down mode to detect the targets. Firstly, in the bottom-up mode, the algorithm extracts the low level image features, such as intensity, standard deviation and Gabor features, to calculate the difference between the current pixel and the pixel around it and use the difference as the bottom-up saliency of the pixel; Then, the algorithm extracts the HOG features of the plane and vehicle targets to train a SVM classifier, which can learn the high level knowledge of the target. When testing on a new image, the classifier uses the knowledge to predict the possibility of appearance of the target as the top-down saliency of each position of the image; Finally, we combine the two saliency maps to get the final saliency map and use it to detect targets in the image. Experiments show that the algorithm can effectively detect the ground mobile targets robustly in complex backgrounds.

A real-time multi-channel high-definition image mosaic system is designed based on FPGA. First, the best matching pointsare obtained by the improved SIFT feature point matching algorithm. Wide Angle camera's internal and external parameters are calculated using the image calibration method. According to sphere reverse projection principle and the camera’s parameters, transform matrix are generated. Then, FPGA can completetransformation,projection,mosaic and display for each high-definition image in parallel.In this paper, thetransform matrix is calculated by image calibration algorithm.Multi-channel high-definition video mosaic system based on FPGA is realized. The design has very strong practicability.

In this paper, the influence of packaging on the high speed performance of photodetector (PD) is systematically and comprehensively studied. Combined with the equivalent circuit, the RF attenuation induced by packaging in PD module is investigated in detail. The microwave transmission performance of the PD module has been analyzed and optimized in three regions: the RF substrate, the connection between the coaxial connector and the substrate, and the parasitic parameters introduced by packaging. With the optimized scheme, a packaged PD module with a 3dB bandwidth of 23GHz is fabricated and its bandwidth has no degradation compared to the photodiode chip. The results indicate that the performance of the PD module can be compensated by optimizing the packaging design and the optimized scheme can be used for PD module which has a higher response speed.

The Jones matrix and the Mueller matrix are main tools to study polarization devices. The Mueller matrix can also be used for biological tissue research to get complete tissue properties, while the commercial optical coherence tomography system does not give relevant analysis function. Based on the LabVIEW, a near real time display method of Mueller matrix image of biological tissue is developed and it gives the corresponding phase retardant image simultaneously. A quarter-wave plate was placed at 45 in the sample arm. Experimental results of the two orthogonal channels show that the phase retardance based on incident light vector fixed mode and the Mueller matrix based on incident light vector dynamic mode can provide an effective analysis method of the existing system.

It is difficult to monitor and predict the crops early diseases in that the crop disease monitoring is usually monitored by visible light images and the availabilities in early warning are poor at present. The features of common nondestructive testing technology applied to the crop diseases were analyzed in this paper. Based on the changeable characteristics of the virus from the incubation period to the onset period of crop activities, the multilevel composite information monitoring scheme were designed by applying infrared thermal imaging, visible near infrared hyperspectral imaging, micro-imaging technology to the monitoring of multilevel information of crop disease infection comprehensively. The early warning process and key monitoring parameters of compound monitoring scheme are given by taking the temperature, color, structure and texture of crops as the key monitoring characteristics of disease. With overcoming the deficiency that the conventional monitoring scheme is only suitable for the observation of diseases with naked eyes, the monitoring and early warning of the incubation and early onset of the infection crops can be realized by the composite monitoring program as mentioned in this paper.

At present,all-fiber coherent Doppler lidar mostly uses acousto-optic modulator (AOM) to modulate frequency of reference light.A kind of new all-fiber coherent Doppler lidar with no acousto-optic modulator was proposed.First,the signal processing used in this system was used to measure the simulated Doppler shift.The simulation results indicate that the more noise is added to the signal,the more errors will be obtained from the calculation. Then the lidar system was utilized to measure the velocity of atmosphere produced by a fan.The results conform very closely to the reference ,whose absolute errors are less than 0.15m/s. The simulation and experiment results validate the accuracy of the lidar system.

The research and testing techniques of friction sensor is an important support for hypersonic aircraft. Compared with the conventional skin friction sensor, the MEMS skin friction sensor has the advantages of small size, high sensitivity, good stability and dynamic response. The MEMS skin friction sensor can be integrated with other flow field sensors whose process is compatible with MEMS skin friction sensor to achieve multi-physical measurement of the flow field; and the micro-friction balance sensor array enable to achieve large area and accurate measurement for the near-wall flow. A MEMS skin friction sensor structure is proposed, which sensing element not directly contacted with the flow field. The MEMS fabrication process of the sensing element is described in detail. The thermal silicon oxide is used as the mask to solve the selection ratio problem of silicon DRIE. The optimized process parameters of silicon DRIE: etching power 1600W/LF power 100 W; SF₆ flux 360 sccm; C₄F₈ flux 300 sccm; O₂ flux 300 sccm. With Cr/Au mask, etch depth of glass shallow groove can be controlled in 30°C low concentration HF solution; the spray etch and wafer rotate improve the corrosion surface quality of glass shallow groove. The MEMS skin friction sensor samples were fabricated by the above MEMS process, and results show that the error of the length and width of the elastic cantilever is within 2 μm, the depth error of the shallow groove is less than 0.03 μm, and the static capacitance error is within 0.2 pF, which satisfy the design requirements.

The measurement of the angle between multiple optical axes is achieved by using a parallel light pipe with a Cassegrain structure. And proposed a method for the use of theodolite auxiliary measurement for this system. The system uses the value of deviation x and y of the crosshair on the two-dimensional plane to represent the vertical angle β 'and the horizontal angle α'. We have found the relationship between this variables by establishing a mathematical model and proved the correctness of this relationship is verified through experimental data by building an experiments while verifying the feasibility of the multi-axis consistency measurement method. The experimental data show that the total error of the optical axis is less than 12 ", which accords with the system index, and shows that the measurement method is real and effective.

Infrared thermography is a fast and effective non-destructive testing method, which has an increasing application in the field of Aeronautics, Astronautic, architecture and medical, et al. Most of the reports about the application of this technology are focus on the specimens of planar, pulse light is often used as the heat stimulation and a plane heat source is generated on the surface of the specimen by the using of a lampshade, however, this method is not suitable for the specimen of non-planar, such as the pipeline. Therefore, in this paper, according the NDT problem of a steel and composite pipeline specimen, ultrasonic and hot water are applied as the heat source respectively, and an IR camera is used to record the temperature varies of the surface of the specimen, defects are revealed by the thermal images sequence processing. Furthermore, the results of light pulse thermography are also shown as comparison, it is indicated that choose the right stimulation method, can get a more effective NDT results for the pipeline specimen.

The photoelectric reconnaissance and detection is the precondition of implementing efficient photoelectric jamming and the important link of electro-optical countermeasures. Starting with the features of laser signal and the characteristic of laser detection device, the limited factors of faint laser detecting technology in application were analyzed, which include the contradiction between of receiving in large field of view and the technology of narrowband spectrum filtering, the contradiction between clear aperture of optical system and angle of view, the limitation of low repeat frequency rate of laser and the limitation of narrow pulse of laser signal. At the same time, the key technologies of faint laser signal detection were analyzed, including detection of faint signal, eliminating parasitic light, high gain optical antenna and protecting detector. What’s more, the application modes in direct detecting laser warning device and scatter interception laser warning device were analyzed.

In order to satisfy the application requirements of spaceborne three dimensional imaging lidar , a prototype of nonscanning multi-channel lidar based on receiver field of view segmentation was designed and developed. High repetition frequency micro-pulse lasers, optics fiber array and Geiger-mode APD, combination with time-correlated single photon counting technology, were adopted to achieve multi-channel detection. Ranging experiments were carried out outdoors. In low echo photon condition, target photon counting showed time correlated and noise photon counting were random. Detection probability and range precision versus threshold were described and range precision increased from 0.44 to 0.11 when threshold increased from 4 to 8.

The study of the relationship between transmittance visibility and PM2.5 concentration under the haze conditions has important theoretical significance for Free Space Optical communication (FSO). In this paper, the influence of PM2.5 concentration on the transmittance, attenuation coefficient and visibility was studied by light scattering theory, and the results by Mie theory and Monte Carlo method were analyzed. At the same time, the effect of PM2.5 particle size distribution on visibility was also analyzed, and the visibility calculated by light scattering method was compared with the visibility measured in Beijing from 2014 to 2016. The result shows that the higher PM2.5 concentration is，the more obvious the multiple scattering effect is. When the mass concentration of PM2.5 is constant, the larger the geometric mean of the particle diameter is, the larger the visibility is. By comparing the visibility measured and the visibility calculated, we can see that when PM2.5 concentration is higher than 100μg/m³ , PM2.5 is the main factor affecting the visibility; and when PM2.5 concentration is lower than 100μg/m³, other factors (such as PM10, wind speed, air pressure and gas molecules) should also need to be considered.

The corner reflector is a kind of passive interference method which commonly used in ship electronic confrontation, there is no significant difference in the echo signal of the ship in the time domain, frequency domain and airspace. The polarization transformation characteristic of the target is intrinsically related to its shape and structure, and the antijamming effect of the target can be solved by using the polarization characteristic. In this paper, polarized scattering data are obtained by simulating ship and corner reflector models with CST software, the polarized invariant and the target polarized shape factor are calculated by polarized scattering data. SVM is used as a classifier to classify the ship and corner reflector based on the polarization invariant and the target polarization shape factor. The result shows that the method it is possible to effectively classify the ship and the corner reflector

Tunable Diode Laser Absorption Spectroscopy (TDLAS) is a non-intrusive method of measurement, which has lots of advantages, such as real-time, fast response, high sensitivity, easy operation, harsh condition applicability and so on. In this paper, the 7173.781201 and 7199.37761 cm^-1 line pair of water vapor were selected for the temperature measurement of the flat flame burner. In order to observe the non-uniform temperature distribution, the Fourier-Hankel transform in the inverse Abel transform was used to convert the integrated temperature, which got by TDLAS, into temperature field.

Streak images obtained by the streak tube imaging lidar (STIL) contain the distance-azimuth-intensity information of a scanned target, and a 3-D reconstruction of the target can be carried out through extracting the characteristic data of multiple streak images. Significant errors will be caused in the reconstruction result by the peak detection method due to noise and other factors. So as to get a more precise 3-D reconstruction, a peak detection method based on Gaussian fitting of trust region is proposed in this work. Gaussian modeling is performed on the returned wave of single time channel of each frame, then the modeling result which can effectively reduce the noise interference and possesses a unique peak could be taken as the new returned waveform, lastly extracting its feature data through peak detection. The experimental data of aerial target is for verifying this method. This work shows that the peak detection method based on Gaussian fitting reduces the extraction error of the feature data to less than 10%; utilizing this method to extract the feature data and reconstruct the target make it possible to realize the spatial resolution with a minimum 30 cm in the depth direction, and improve the 3-D imaging accuracy of the STIL concurrently.

The vanadyl phthalocyanine (VOPc) organic thin film transistors (OTFTs) were fabricated on the various organosilane self-assembled monolayer (SAM) modified substrates. And the effect of the surface properties on the performance of these transistors was studied. The atomic force morphologies and X-ray diffraction (XRD) spectrums of vanadyl phthalocyanine films on different SAM-modified surfaces were studied. They reveal that the terminal functional groups of organosilane affect the growth of VOPc film and device performance. The VOPc film on octadecyltrichlorosilane (OTS) modified substrate has larger crystal size and effective crystal thickness than those on phenyltrichlorosilane (PTS), 1H,1H,2H,2H-Perfluorodec-yltrichlorosilane (FDTS) as well as non-modified substrate, which contributes the mobility of corresponding device several and several dozen times relative to other ones. The effective crystal thickness and crystal grain size of VOPc film on PTS is between that on OTS treated and that on non-modified substrate due to the stronger attractive force between VOPc and SiO2. The VOPc films’ performance and effective crystal thickness on FDTS treated are worse than that on PTS due to the existents of attractive force between –CF₃ and VOPc.

Electron bombardment of semiconductor gain as the main characteristics of electronic bombardment devices affect the overall performance of the device. According to weak signal detection theory, developed a set of multiplying electron gain test system including pre-amplifier circuit and FPGA-based high-speed signal acquisition system. The tinned semiconductor sample was tested experimentally, for the relationship between gain performance and incident electron energy. The experimental with incident electron energy(1500-2000eV) bombardment 65μm of semiconductor sample, results show the multiply electron gain with the increase of the incident electron energy, which will provide theoretical basis and technical support to further manufacture of high performance electron bombarded semiconductor sensors.

We demonstrate highly efficient organic ultraviolet photodetectors using 4,4’,4’’ -tris[3-methyl-pheny(phenyl) amino] triphenylamine (m-MTDATA) and aluminum Tris(8-Hydroxyquinolinate) Synonym Alq₃). The optimized photodetector delivers a photocurrent of 1.40 mA/cm² at10 V, corresponding to a response of 127 mA/W under an illumination of 375 nm UV light irradiation with an intensity of 10.5 mW/cm² and a detectivity of 2.15×10¹¹ cm Hz^1/2 /W. The high response is attributed to the larger band offset at m-MTDATA/ Alq₃ heterojunction, the suppression of radiative decay of m-MTDATA and efficient electron transfer from m-MTDATA to Alq3. The working mechanism of harvesting high performance is also discussed in detail.

Because there is no practical method to validate the precision of atmospheric transmittance for earth based infrared optical system measuring flying aircraft, this paper applies multiple linear regression to analyze the measured meteorological parameters and atmospheric transmittance, and points out that: 1) the effects of air pressure and visibility on atmospheric transmittance are contrary with physical laws; 2) among all the meteorological parameters, the angle of elevation has the greatest impact on atmospheric transmittance. By comparing with practical result of the experiment, it is found there is big difference. At last, conclusion is drawn that the accuracy of atmospheric transmittance provided by one infrared optical system is not high.

A new type of tunable diode spectroscopy sensor based on an external cavity quantum cascade laser (ECQCL) and a quartz crystal tuning fork (QCTF) were used for quantitative analysis of volatile organic compounds. In this work, the sensor system had been tested on different gasoline sample analysis. For signal processing, the self-established interpolation algorithm and multiple linear regression algorithm model were used for quantitative analysis of major volatile organic compounds in gasoline samples. The results were very consistent with that of the standard spectra taken from the Pacific Northwest National Laboratory (PNNL) database. In future, The ECQCL sensor will be used for trace explosive, chemical warfare agent, and toxic industrial chemical detection and spectroscopic analysis, etc.

This paper reports on a macroporous silicon arrays with high aspect ratio, the pores of which are of 162, 205, 252, 276μm depths with 6, 10, 15 and 20 μm diameters respectively, prepared by Multiplex Inductively Coupled Plasma (ICP) etching. It was shown that there are very differences in process of high aspect ratio microstructures between the deep pores, a closed structure, and deep trenches, a open structure. The morphology and the aspect ratio dependent etching were analyzed and discussed. The macroporous silicon etched by ICP process yield an uneven, re-entrant, notched and ripples surface within the pores. The main factors effecting on the RIE lag of HARP etching are the passivation cycle time, the pressure of reactive chamber, and the platen power of ICP system.

The quantum efficiency of the dual bands quantum well infrared photodetectors(QWIP) has been widely concerned in recent years. A novel structure for the dual-band quantum well infrared detectors which is based on GaAs/AlGaAs designed in this paper is aimed to improve the absorption efficiency. The structure replaces the conventional grating with a metallic grating based on surface plasmon polaritons(SPPS), and we further insert a metal structure in the periodic quantum well layer. The simulation result shows that the use of the different shapes of the metal holes can remarkably improve the optical coupling efficiency due to the surface plasmon effect. By optimizing parameters of the structure, it can work in the dual infrared bands of 3-5um and 8-12um. Moreover, the absorption rate increased by 20% compared with traditional structure of Dual-band QWIP.

Hyperspectral image is a three-dimensional data cube which describes spatial information and spectral information of the scene. The anomaly detection technique can detect the targets which have difference between the image and the background without priori information. Kernel independent component analysis(KICA) is a method of mapping hyperspectral data into the kernel space for feature extraction. In this paper, the hyperspectral image is subjected to abnormal information detection based on KICA. First, we calculate the kernel matrix K in order to map the data to high-dimensional space for whitening and dimension reduction processing. Then we utilize the FastICA algorithm to extract the core independent component (KIC). Finally, the extracted independent components with the most abnormal information are analyzed by RX operator, kernel RX operator and abundance quantization method. Comparing with the simulation result and the detected result by RX method, the representation shows the algorithm based on KICA has better detection performance.

In the field of low illumination image sensor, the noise of the latest scientific-grade CMOS image sensor is close to EMCCD, and the industry thinks it has the potential to compete and even replace EMCCD. Therefore we selected several typical sCMOS and EMCCD image sensors and cameras to compare their performance parameters. The results show that the signal-to-noise ratio of sCMOS is close to EMCCD, and the other parameters are superior. But signal-to-noise ratio is very important for low illumination imaging, and the actual imaging results of sCMOS is not ideal. EMCCD is still the first choice in the high-performance application field.

Bias thermal stability of a Fiber-Optic Gyroscope using Polarization-Maintaining Photonic Crystal (PM-PCF) was studied. And the thermal sensitivity of birefringence in PM-PCF and polarization cross talking in fiber coil was measured. By using an OCDP method, the polarization cross talking causing phase error of the FOG was analyzed. The contrast experiment result of the FOGs with PM-PCF coil and PMF coil showed that using PM-PCF instead of PMF can improve the FOG’s bias thermal stability by about 50%.

Multi-band IR imaging system has many applications in security, national defense, petroleum and gas industry, etc. So the relevant technologies are getting more and more attention in rent years. As we know, when used in missile warning and missile seeker systems, multi-band IR imaging technology has the advantage of high target recognition capability and low false alarm rate if suitable spectral bands are selected. Compared with traditional single band IR imager, multi-band IR imager can make use of spectral features in addition to space and time domain features to discriminate target from background clutters and decoys. So, one of the key work is to select the right spectral bands in which the feature difference between target and false target is evident and is well utilized. Multi-band IR imager is a useful instrument to collect multi-band IR images of target, backgrounds and decoys for spectral band selection study at low cost and with adjustable parameters and property compared with commercial imaging spectrometer. In this paper, a multi-band IR imaging system is developed which is suitable to collect 4 spectral band images of various scenes at every turn and can be expanded to other short-wave and mid-wave IR spectral bands combination by changing filter groups. The multi-band IR imaging system consists of a broad band optical system, a cryogenic InSb large array detector, a spinning filter wheel and electronic processing system. The multi-band IR imaging system's performance is tested in real data collection experiments.

A kind of high accuracy Photo-electric auto-collimator based on PSD was designed. The integral structure composed of light source, optical lens group, Position Sensitive Detector (PSD) sensor, and its hardware and software processing system constituted. Telephoto objective optical type is chosen during the designing process, which effectively reduces the length, weight and volume of the optical system, as well as develops simulation-based design and analysis of the auto-collimator optical system. The technical indicators of auto-collimator presented by this paper are: measuring resolution less than 0.05″; a field of view is 2ω=0.4° × 0.4°; measuring range is ±5′; error of whole range measurement is less than 0.2″. Measuring distance is 10m, which are applicable to minor-angle precise measuring environment. Aberration analysis indicates that the MTF close to the diffraction limit, the spot in the spot diagram is much smaller than the Airy disk. The total length of the telephoto lens is only 450mm by the design of the optical machine structure optimization. The autocollimator’s dimension get compact obviously under the condition of the image quality is guaranteed.

Laser communication, designation, and ranging are point to point and have a high degree of specificity, current laser detection, such as laser warning receiver system, could detect the scattering laser from the off-axis distance by scattering track on natural aerosols, which is helpful to locate the laser source. However, the intensity of the scattering laser is extremely weak and affected by many factors, in order to evaluate the detection characteristic, a simplified model of off-axis detection for scattering laser in the lower atmosphere based on the Mie scattering theory is presented in this paper, the performances of the off-axis laser detection in different conditions such as off-axis distance, visibility, incidence angle, and delay time are investigated.

The photoelectric theodolite is an important scheme to realize the tracking, detection, quantitative measurement and performance evaluation of weapon systems in ordnance test range. With the improvement of stability requirements for target tracking in complex environment, infrared scene simulation with high sense of reality and complex interference has become an indispensable technical way to evaluate the track performance of photoelectric theodolite. And the tail flame is the most important infrared radiation source of the weapon system. The dynamic tail flame with high reality is a key element for the photoelectric theodolite infrared scene simulation and imaging tracking test. In this paper, an infrared simulation method for the full-path tracking of tail flame by photoelectric theodolite is proposed aiming at the faint boundary, irregular, multi-regulated points. In this work, real tail images are employed. Simultaneously, infrared texture conversion technology is used to generate DDS texture for a particle system map. Thus, dynamic real-time tail flame simulation results with high fidelity from the theodolite perspective can be gained in the tracking process.

Vacuum-semiconductor hybrid photodetector is a new kind of photoelectric detecting device. In this paper, the basic structure and principle of electron bombarded avalanche diode hybrid photodetector are introduced. Then a sample of electron bombarded silicon avalanche diode hybrid photodetector is successfully fabricated. The results show that the response range of the photodetector is 300nm-800nm, and the electron bombarded gain is more than 600 times under the high voltage of -8000V. The breakdown voltage of silicon avalanche diode avalanche is about -202V. The dark current of device under linear avalanche mode with gain equals 30 is about 3.2nA. The total gain of the tube after electron bombarded gain and avalanche gain are cascaded can be up to 1.5 × 104.

In the artificially affected weather, the detection of cloud droplets particles provides an important reference for the effective impact of artificial weather. Digital holography has the unique advantages of full-field, non-contact, no damage, real-time and quantification. In this paper, coaxial digital holography is used to record the polyethylene standard particles and aluminum scrap, and some important parameters, such as three-dimensional coordinate spatial distribution and particle size, will be obtained by the means of analyzing the digital hologram of the particle. The experimental results verify the feasibility of the coaxial digital holographic device applied to the measurement of the cloud parameters, and complete the construction of the coaxial digital holographic system and the measurement of the particles.

According to the working principle of the binocular photoelectric instrument optical axis parallelism digital calibration instrument, and in view of all components of the instrument, the various factors affect the system precision is analyzed, and then precision analysis model is established. Based on the error distribution, Monte Carlo method is used to analyze the relationship between the comprehensive error and the change of the center coordinate of the circle target image. The method can further guide the error distribution, optimize control the factors which have greater influence on the comprehensive error, and improve the measurement accuracy of the optical axis parallelism digital calibration instrument.

An array extended blackbody is designed to quantitatively measure and evaluate the performance of infrared imaging systems. The theory, structure, control software and application of blackbody are introduced. The parameters of infrared imaging systems such as the maximum detectable range, detection sensitivity, spatial resolution and temperature resolution can be measured.

Aerosol extinction coefficient profile is an essential parameter for atmospheric radiation model. But it is difficult to get the full aerosol extinction profile from the ground to the tropopause especially in near ground precisely using backscattering lidar. A combined measurement of side-scattering, backscattering and Raman-scattering lidar is proposed to retrieve the aerosol extinction coefficient profile from the surface to the tropopause which covered a dynamic range of 5 orders. The side-scattering technique solves the dead zone and the overlap problem caused by the traditional lidar in the near range. Using the Raman-scattering the aerosol lidar ratio (extinction to backscatter ratio) can be obtained. The cases studies in this paper show the proposed method is reasonable and feasible.

Single photon satellite laser altimeter is based on Geiger model, which has the characteristics of small spot, high repetition rate etc. In this paper, for the slope terrain, the distance of error’s formula and numerical calculation are carried out. Monte Carlo method is used to simulate the experiment of different terrain measurements. The experimental results show that ranging accuracy is not affected by the spot size under the condition of the flat terrain, But the inclined terrain can influence the ranging error dramatically, when the satellite pointing angle is 0.001° and the terrain slope is about 12°, the ranging error can reach to 0.5m. While the accuracy can’t meet the requirement when the slope is more than 70°. Monte Carlo simulation results show that single photon laser altimeter satellite with high repetition rate can improve the ranging accuracy under the condition of complex terrain. In order to ensure repeated observation of the same point for 25 times, according to the parameters of ICESat-2, we deduce the quantitative relation between the footprint size, footprint, and the frequency repetition. The related conclusions can provide reference for the design and demonstration of the domestic single photon laser altimetry satellite.

Study the noise by detectors and background light ,we find that the influence of background noise on the detection is more than that of itself. Therefore, base on the fiber coupled beam splitting technique, the small area detector is used to replace the large area detector. It can achieve high signal-to-noise ratio (SNR) and reduce the speckle interference of the background light. This technique is expected to solve the bottleneck of large field of view and high sensitivity.

The paper introduces a new electronic image stabilization approach based on block matching. It chooses some fixed points which form a grid at the present frame and find out the corresponding points at the next frame. The better points are found out by the center-reservation algorithm. We can obtain the global motion estimation parameters from local motion parameters. Then the stable image sequence can be obtained by compensating image frames. Experimental results show that the algorithm can stabilize image sequence robustly and effectively.

As one of the typical wide band-gap semiconductor materials, the CdZnTe material has high detection efficiency and excellent energy resolution for the hard X-ray and the Gamma ray. The generated signal of the CdZnTe detector needs to be transformed to the pseudo-Gaussian pulse with a small impulse-width to remove noise and improve the energy resolution by the following nuclear spectrometry data acquisition system. In this paper, the multi-stage pseudo-Gaussian shaping-filter has been investigated based on the nuclear electronic principle. The optimized circuit parameters were also obtained based on the analysis of the characteristics of the pseudo-Gaussian shaping-filter in our following simulations. Based on the simulation results, the falling-time of the output pulse was decreased and faster response time can be obtained with decreasing shaping-time τ_s-k. And the undershoot was also removed when the ratio of input resistors was set to 1 to 2.5. Moreover, a two stage sallen-key Gaussian shaping-filter was designed and fabricated by using a low-noise voltage feedback operation amplifier LMH6628. A detection experiment platform had been built by using the precise pulse generator CAKE831 as the imitated radiation pulse which was equivalent signal of the semiconductor CdZnTe detector. Experiment results show that the output pulse of the two stage pseudo-Gaussian shaping filter has minimum 200ns pulse width (FWHM), and the output pulse of each stage was well consistent with the simulation results. Based on the performance in our experiment, this multi-stage pseudo-Gaussian shaping-filter can reduce the event-lost caused by pile-up in the CdZnTe semiconductor detector and improve the energy resolution effectively.

Cloud is an important natural phenomenon, and its radiation causes serious interference to infrared detector. Based on fractal and statistical data, a method is proposed to realize cloud background simulation, and cloud infrared radiation data field is assigned using satellite radiation data of cloud. A cloud infrared radiation simulation model is established using matlab, and it can generate cloud background infrared images for different cloud types (low cloud, middle cloud, and high cloud) in different months, bands and sensor zenith angles.

Total ionizing dose effect is a major threat to space applications of CCD, which leads to the decrease of CCD saturation output voltage and the increase of dark signal. This paper investigated CCD and its readout circuit for experimental samples of different channel width to length ratio of MOSFET, and readout circuit amplifier, and CCD. The irradiation source was 60Co- gamma ray. through testing the parameters degradation of MOSFET and amplifier degradation, the generation and annealing law of irradiation induced defects in MOS single tube are analyzed. Combined with the radiation effect of amplifier and CCD, The correlation of radiation damage of the MOSFET and the readout circuit amplifier and CCD parameter degradation is established. Finally, this paper reveals the physical mechanism of ionizing radiation damage of the readout circuit. The research results provide a scientific basis for the selection of anti-radiation technology and structure optimization of domestic CCD.

Typical natural backgrounds include land, sea, desert, sky and so on, and experimental measurement is an effective means to obtain background radiation data. Because the background infrared radiation is affected by season, weather and the angle of solar radiation, it is necessary to collect environmental parameters at the same time during testing. The screening and collection of major environmental parameters is crucial for subsequent radiation data processing. In view of this problem, first of all, the influence of environmental reference on background infrared radiation was theoretically calculated by MODTRAN software, and the main parameters were screened out. A test program for radiation measurement of natural background is formed, which is used as a reference for the design of background infrared radiation measurement.

It has a widely applications in robot vision and 3D measurement for binocular stereoscopic measurement technology. And the measure precision is an very important factor, especially in 3D coordination measurement, high measurement accuracy is more stringent to the distortion of the optical system. In order to improving the measurement accuracy of imaging points, to reducing the distortion of the imaging points, the optical system must be satisfied the requirement of extra low distortion value less than 0.1％, a transmission visible optical lens was design, which has characteristic of telecentric beam path in image space, adopted the imaging model of binocular stereo vision, and imaged the drone at the finity distance. The optical system was adopted complex double Gauss structure, and put the pupil stop on the focal plane of the latter groups, maked the system exit pupil on the infinity distance, and realized telecentric beam path in image space. The system mainly optical parameter as follows: the system spectrum rangement is visible light wave band, the optical effective length is f ’=30mm, the relative aperture is 1/3, and the fields of view is 21°. The final design results show that the RMS value of the spread spots of the optical lens in the maximum fields of view is 2.3μm, which is less than one pixel(3.45μm); the distortion value is less than 0.1%, the system has the advantage of extra low distortion value and avoids the latter image distortion correction; the proposed modulation transfer function of the optical lens is 0.58(@145 lp/mm), the imaging quality of the system is closed to the diffraction limited; the system has simply structure, and can satisfies the requirements of the optical indexes. Ultimately, based on the imaging model of binocular stereo vision was achieved to measuring the drone at the finity distance.

In this letter, Raman spectroscopy was used to study the variation of transfer graphene. First, the Raman spectroscopy of chemical vapor deposition (CVD)-grown monolayer graphene was compared with that of mechanical exfoliated graphene, the 2D Raman band frequency of monolayer graphene grown on copper foils by CVD showed a blue shift upto 12 cm^-1 . Then, the CVD-grown graphene on copper substrates was transferred to SiO₂(300nm)/Si by wet transfer method, that caused a 2D-band redshift by 15cm^-1 compared with the graphene before transferred, besides, the defects appeared in some regions. According to the changes of Raman spectrum, the strain was confirmed as the most important reason in the letter. The observation of the Raman shifts helps us to gain more physical insights into the transfer of graphene.

On the basis of the conventional Jamin interferometer,the improved measuring method is proposed that using a polarization type reentrant Jamin interferometer measures atmospheric aerosol absorption coefficient under the photothermal effect.The paper studies the relationship between the absorption coefficient of atmospheric aerosol particles and the refractive index change of the atmosphere.In Matlab environment, the variation curves of the output voltage of the interferometer with different concentration aerosol samples under stimulated laser irradiation were plotted.Besides, the paper also studies the relationship between aerosol concentration and the time required for the photothermal effect to reach equilibrium.When using the photothermal interferometry the results show that the time required for the photothermal effect to reach equilibrium is also increasing with the increasing concentration of aerosol particles,the absorption coefficient and time of aerosol in the process of nonequilibrium are exponentially changing.

Based on a 640×512 cooled staring focal plane array (FPA) detector, pixel size 15μm×15μm, a long focal length mid-wavelength infrared optical system was designed. In this paper, the working wavelength is 3μm~5μm, the temperature range is -30°C~+50°C, this system can realize 1000mm focal length, the F-number is 4, the full field of view is 0.70°, satisfy 100% cold shield efficiency. A re-imaging refractive system was adopted in this designed optical system consists of a main objective group and a projection group. First of all, the structural selection and the initial parameter calculation were introduced. Secondly, on the basis of variety of the temperature, a focusing len was presented in this system to adjust to produce a clear image. Last but not the least, to improve image quality and environment adaptability, the analysis of temperature change and ghost image were described particularly. The design results prove that at the spatial frequency of 33 lp/mm, the axis MTF of the optical system is greater than 0.35, the system can offer a high resolution and excellent images, and it has the advantages of good adaptability, simple structure, easy to adjust, and high transmittance.

A high energy of b-cut Tm, Ho:YAlO₃ laser is reported in the paper. The laser operated in acousto-optical Qswitched mode at 2.12 μm. The output average power of 9.61 W was achieved at the pulse repetition frequency of 10 kHz ,and the power of 11.6 W was acquired in continuous wave mode. Moreover, the energy per pulse of 0.961 mJ in 64.4 ns was acquired at 10 kHz with a 14.92-kW peak power.

This paper presents a new digital watermarking method, which majors improvement method realised based on single-chip FPGA. The procedure includes dividing the input digital image by block, block selection, sorting the pixel values within the blocks. The data is embedded by using new difference and new histogram-modification-strategy. The definition of new difference takes the position of maximum and the second large value pixel into account. Which is help for to the blocks, in which maximum value equal to the second largest. This algorithm can use these pixel blocks to embed data in. The key algorithm is based on the FPGA, using Verilog HDL language and graphical input method to design on the Quartus II 13.0 software platform. And the processed pixel value will be passed to the computer, providing experimental data for analysis and comparative.

Aiming at the problem of any fault and wrong code in the practical application of photoelectric shaft encoder, a fast and accurate encoder fault analysis system is researched from the aspect of Moire fringe photoelectric signal processing. DSP28335 is selected as the core processor and high speed serial A/D converter acquisition card is used. And temperature measuring circuit using AD7420 is designed. Discrete data of Moire fringe error signal is collected at different temperatures and it is sent to the host computer through wireless transmission. The error signal quality index and fault type is displayed on the host computer based on the error signal identification method. The error signal quality can be used to diagnosis the state of error code through the human-machine interface.

Far ultraviolet earth night airglow is related to total electron content(TEC) of Ionosphere. Observing the night airglow nadir at OI 135.6nm emission produced by ionospheric O+ and e recombination can get the distribution of ionosphere TEC. In this paper, a compact of ionospheric FUV photometer developed for micro satellite will be introduced. The instrument works in photo-counting mode to achieve high sensitivity for weak night airglow radiation detection. The design of this photo-counting detector will be described in detail.

For the high precision requirement of spaceborne low light remote sensing camera optical registration, optical registration of dual channel for CCD and EMCCD is achieved by the high magnification optical registration system. System integration、optical registration and accuracy of optical registration scheme for spaceborne low light remote sensing camera with short focal depth and wide field of view is proposed in this paper. It also includes analysis of parallel misalignment of CCD and accuracy of optical registration. Actual registration results show that imaging clearly, MTF and accuracy of optical registration meet requirements, it provide important guarantee to get high quality image data in orbit.

Vitamin is the organic compound and necessary for animal physiological maintenance. The rapid determination of the content of different vitamins in premix feed can help to achieve accurate diets and efficient feeding. Compared with high-performance liquid chromatography and other wet chemical methods, near-infrared spectroscopy is a fast, non-destructive, non-polluting method. 168 samples of premix feed were collected and the contents of vitamin A, vitamin E and vitamin D₃ were detected by the standard method. The near-infrared spectra of samples ranging from 10 000 to 4 000 cm^-1 were obtained. Partial least squares regression (PLSR) and support vector machine regression (SVMR) were used to construct the quantitative model. The results showed that the RMSEP of PLSR model of vitamin A, vitamin E and vitamin D₃ were 0.43×10⁷ IU/kg, 0.09×10⁵ IU/kg and 0.17×10⁷ IU/kg, respectively. The RMSEP of SVMR model was 0.45×10⁷ IU/kg, 0.11×10⁵ IU/kg and 0.18×10⁷ IU/kg. Compared with nonlinear regression method (SVMR), linear regression method (PLSR) is more suitable for the quantitative analysis of vitamins in premix feed.

In this paper, an improved Interferometer was introduced which based on traditional Jamin Interferometer to solve the twin image where appear in on-axis holographic. Adjust the angle of reference light and object light that projected onto the CCD by change the reflector of the system to separate the zero order of diffraction, the virtual image and the real image, so that could eliminate the influence of the twin image. The result of analysis shows that the system could be realized in theory. After actually building the system, the hologram of the calibration plate is reconstructed and the result is shown to be feasible.

Projector calibration is crucial for a camera-projector three-dimensional (3-D) structured light measurement system, which has one camera and one projector. In this paper, a novel projector calibration method is proposed based on digital image correlation. In the method, the projector is viewed as an inverse camera, and a plane calibration board with feature points is used to calibrate the projector. During the calibration processing, a random speckle pattern is projected onto the calibration board with different orientations to establish the correspondences between projector images and camera images. Thereby, dataset for projector calibration are generated. Then the projector can be calibrated using a well-established camera calibration algorithm. The experiment results confirm that the proposed method is accurate and reliable for projector calibration.

The change of heavy metal content in water environment, soil and plant can reflect the change of heavy metal pollution in ecological environment, and it is important to monitor the trend of heavy metal pollution in eco-environment by using water environment, soil and heavy metal content in plant. However, the content of heavy metals in nature is very low, the background elements of water environment, soil and plant samples are complex, and there are many interfering factors in the EDXRF system that will affect the spectral analysis results and reduce the detection accuracy. Through the contrastive analysis of several heavy metal elements detection methods, it is concluded that the EDXRF method is superior to other chemical methods in testing accuracy and method feasibility when the heavy metal pollution in soil is tested in ecological environment.

In this paper, the key technologies of single photon detection in airborne laser ranging are analyzed. Aiming at the engineering application, we propose the next investigation of single photon detection. 1) the compensation of pulse propagation in atmosphere; 2) the problem of ranging accuracy for moving targets; 3) high accuracy optical axis coherence of receiving and transmitting. Further research can improve the airborne adaptability of single photon ranging system.

The presence of photon reflection in the input surface of the microchannel plate causes photon scattered noise, which reduces the signal-to-noise ratio of the micro-light image intensifier. The input surface of the microchannel plate was covered with ion barrier film, which had a great impact on the input surface photon reflection. In order to study the effects of ion barrier film Al₂O₃ on the photon reflection characteristics of microchannel plate input surface, this paper uses the spectrophotometer system to test the 4 groups filmed and un-filmed microchannel plate input surface reflectivity in the 200-800nm band range.The results show that the reflectivity of the microchannel plate with ion barrier film can be kept below 4% and about 2.0% lower than that of the un-filmed microchannel plate; and in the short wave interval, The amplitude of the reflectivity of the filmed and un-filmed microchannel plate is larger,the variation of the long wave interval is relatively gentle.That is valuable to reduce photon scattered noise of microchannel plate.

The traditional temperature measurement system used the ratio of stokes light and anti-stokes light to demodulate the temperature, and there was an error when the ratio used directly. The propagation speed of stokes light and anti-stokes light in the same fiber was different because of dispersion effect. The two kinds of reflected light were obtained by photoelectric converter at different time when the scattering occurred at the same place. Therefore, there was a time warping between the two signals after data acquisition. This phenomenon would lead to measurement error in the process of demodulating temperature. A new method of error correction for the distributed temperature measurement system was used to eliminate the signal dislocation by correcting the stokes signal. In the absence of correction, the antistokes signal peak and the stokes signal peak occurred in different place, which leaded to errors in the process of demodulating temperature. This correcting method was used. The demodulation error was reduced from 2.3 °C to 1.2 °C. The shortest time was 4.96s when detected temperature rise rate was not less than 5 °C/min in the case of 10km fiber carried by this system. It was showed that this technique could improve the performance of the traditional distributed fiber Raman temperature measurement system, and it would have a good aspect.

The motion of soliton centroid in two-dimensional (2D) Bose-Einstein condensate (BEC) is investigated by using the time-dependent variational method in this paper. Similar to the classical 2D harmonic oscillator’s motion equation, the Gaussian trial function with wavepacket centroid coordinates is chosen to get the motion equation of centroid. The Lissajous figures of trajectory are discovered for the first time by solving the motion equations of different initial conditions. This not only proves that the matter wave soliton possesses the motion characteristics of classical particles and shows macroscopic quantum properties, but also provides a new tool for the study of BEC.

10×10 matrix-anode is developed by high-temperature co-fired ceramics (HTCC) technology. Based on the new matrix–anode, a new kind of photon counting imaging detector - 10×10 matrix-anode MCP-PMT is developed, and its performance parameters are tested. HTCC technology is suitable for the MCP-PMT’s air impermeability and its baking process. Its response uniformity is better than the metal-ceramic or metal-glass sealing anode, and it is also a promising method to realize a higher density matrix-anode.

Infrared smoke is mainly used for shielding, blind, deception and recognition on the battlefield. The traditional shelter smoke is mainly placed in the friendly positions or positions between the friendly positions and enemy positions, to reduce the enemy observation post investigative capacity. The passive interference capability of the smoke depends on the infrared extinction ability of the smoke. The infrared transmittance test is an objective and accurate representation of the extinction ability of the smoke. In this paper, a method for testing the spectral transmittance of infrared smoke interference is introduced. The uncertainty of the measurement results is analyzed. The results show that this method can effectively obtain the spectral transmittance of the infrared smoke and uncertainty of the measurement is 7.16%, which can be effective for the smoke detection, smoke composition analysis, screening effect evaluation to provide test parameters support.

In this work, a texture mapping scheme with massive data is proposed based on quadtree for multi-level scene modeling. A simplified LOD model is established for the multi-resolution texture data which enhance the fidelity of multilevel target simulation in scene. By predictable appreciation according to viewpoint displacement in real-time simulation, the correspongding nodes and level details of quadtree are confirmed when the dynamical scene is loading. This mean effectively decreases the schedule data in real-time simulation. A validation experiment has been performed to certificate the availabitity and improvement.

The paper proposes a visual tracking method based on deep learning without online model updating. In consideration of the advantages of deep learning in feature representation, deep model SSD (Single Shot Multibox Detector) is used as the object extractor in the tracking model. Simultaneously, the color histogram feature and HOG (Histogram of Oriented Gradient) feature are combined to select the tracking object. In the process of tracking, multi-scale object searching map is built to improve the detection performance of deep detection model and the tracking efficiency. In the experiment of eight respective tracking video sequences in the baseline dataset, compared with six state-of-the-art methods, the method in the paper has better robustness in the tracking challenging factors, such as deformation, scale variation, rotation variation, illumination variation, and background clutters, moreover, its general performance is better than other six tracking methods.

The magnetometer which is based on the coherence population trapping theory, works by exciting atoms with two modulated coherent light fields and obtaining magnetic resonance signals containing magnetic field intensity information. In view of the problem of measuring blind area in this scheme, the direction characteristics of CPT resonance signal are analyzed. A dark state coupling measurement scheme based on two groups of modulated light fields is proposed. The system performance based on this scheme is verified by the all-optical sensing experiment system. Experimental results show that the resonance signal with higher signal to noise ratio could be obtained by using the dark state coupling measurement technology. This effectively eliminates the blind area of the CPT magnetometer and avoids losing lock of system. As a result, sufficient system stability performance could be obtained in omnidirectional measurement of magnetic field.

When laser propagate in the atmosphere, due to aerosol scattering and absorption, laser energy will continue to decline, affecting the effectiveness of the laser effect. Based on the Monte Carlo method, the relationship between the photon spatial energy distributions of the laser wavelengths of 10.6μm in marine, sand-type, water-soluble and soot aerosols ,and the propagation distance, visibility and the divergence angle were studied. The results show that for 10.6μm laser, the maximum number of attenuation of photons arriving at the receiving plane is sand-type aerosol, the minimal attenuation is water soluble aerosol; as the propagation distance increases, the number of photons arriving at the receiving plane decreases; as the visibility increases, the number of photons arriving at the receiving plane increases rapidly and then stabilizes; in the above cases, the photon energy distribution does not deviated from the Gaussian distribution; as the divergence angle increases, the number of photons arriving at the receiving plane is almost unchanged, but the photon energy distribution gradually deviates from the Gaussian distribution.

Infrared polarization detection technology has unique advantages in the field of target detection and identification because of using the polarization information of radiation. The mechanism of infrared polarization is introduced. Comparing with traditional infrared detection distance model, infrared detection operating range and Signal to Noise Ratio (SNR) model is built according to the polarization degree and noise. The influence of polarization degree on the SNR of infrared system is analyzed. At last, the basic condition of polarization detection SNR better than traditional infrared detection SNR is obtained.

Using SolidWorks software, the finite element modal analysis of a vehicle-borne pollution monitoring lidar cabin is carried out. The lidar cabin for the integrated lidar can ensure that the lidar system has good maneuverability and can effectively monitor the emission of air pollution. Since lidar is an integrated system of optics, mechanism, electricity and calculation, the performance of the cabin is directly related to the safety of the equipment and the lidar to work properly. Firstly, the cubic structure is modeled to simulate the cubic structure. Then, the model of the cabin model is analyzed by using the simulation plug-in, and the first 10 modes and natural frequencies are analyzed and recorded. The calculation results show that the cabin is dominated by bending vibration, and the amplitude area is concentrated in the opening of some windows and doors on each board. Therefore, we should increase the number of reinforcement bars or the strength of the skeleton in the vicinity of the door and window. At the same time, to avoid the resonance and ensure the precision of the optical elements and the electrical components and avoid structural damage of the cabin, the incentive frequency should be keep away from the natural frequency of the cabin. The vehicle-borne lidar system has been put into operation, and the analysis results have direct meaning to the transport of the cabin and the normal work.

This paper analyzes the development status of the infrared polarization imaging system. According to the application need of medium wave infrared (MWIR) polarization image, this paper proposes a MWIR polarization coaperture optical system. The system is composed of the front co-aperture optical system and the rear sub-aperture optical system. The rear separate aperture optical system includes four polarization channels. Each channel adopts a 1/4 wave plate and a linear polarizers to obtain three line Stokes polarization components and one circularly Stokes polarization components Thus the system could achieve full polarization imaging. According to the detector and the corresponding application needs, the calculation and optical system design were completed. After the design, the MTF of the optical system is more than 0.3@17lp/mm. The maximum RMS spot diameter is less than the size of detector pixel and a single pixel energy concentration is greater than 80%.

Terahertz digital holography, which can be used in nondestructive testing and other fields, is the effective combination of terahertz imaging and digital holography. The measurement accuracy may be influenced by the low energy of terahertz source and other factors; therefore it is very important to study denoising algorithms of terahertz digital holographic images. In this paper, optimally weighted bilateral filter (WBF) is applied in the preprocessing of guide image acquired by guided bilateral filter (GBF). This method can eliminate the noise in terahertz digital holography reconstructed image. We compare this algorithm with the original GBF with iterative reweighted least squares algorithm (IRLS). The experimental results show that the preprocessing method is better than the original algorithm.

Objective: Chinese potato staple food strategy clearly pointed out the need to improve potato processing, while the bottleneck of this strategy is technology and equipment of selection of appropriate raw and processed potato. The purpose of this paper is to summarize the advanced raw and processed potato detection methods. Method: According to consult research literatures in the field of image recognition based potato quality detection, including the shape, weight, mechanical damage, germination, greening, black heart, scab potato etc., the development and direction of this field were summarized in this paper. Result: In order to obtain whole potato surface information, the hardware was built by the synchronous of image sensor and conveyor belt to achieve multi-angle images of a single potato. Researches on image recognition of potato shape are popular and mature, including qualitative discrimination on abnormal and sound potato, and even round and oval potato, with the recognition accuracy of more than 83%. Weight is an important indicator for potato grading, and the image classification accuracy presents more than 93%. The image recognition of potato mechanical damage focuses on qualitative identification, with the main affecting factors of damage shape and damage time. The image recognition of potato germination usually uses potato surface image and edge germination point. Both of the qualitative and quantitative detection of green potato have been researched, currently scab and blackheart image recognition need to be operated using the stable detection environment or specific device. The image recognition of processed potato mainly focuses on potato chips, slices and fries, etc. Conclusion: image recognition as a food rapid detection tool have been widely researched on the area of raw and processed potato quality analyses, its technique and equipment have the potential for commercialization in short term, to meet to the strategy demand of development potato as staple food in China.

The electric vehicles (EV) have become accepted by increasing numbers of people for the environmental-friendly advantages. A novel way to charge the electric vehicles is through wireless power transfer (WPT). The wireless power transfer is a high power transfer system. The high currents flowing through the transmitter and receiver coils increasing temperature affects the safety of person and charging equipment. As a result, temperature measurement for wireless power transfer is needed. In this paper, a temperature measurement system based on optical fiber temperature sensors for electric vehicle wireless power transfer is proposed. Initially, the thermal characteristics of the wireless power transfer system are studied and the advantages of optical fiber sensors are analyzed. Then the temperature measurement system based on optical fiber temperature sensor is designed. The system consists of optical subsystem, data acquisition subsystem and data processing subsystem. Finally, the system is tested and the experiment result shows that the system can realize 1°C precision and can acquire real-time temperature distribution of the coils, which can meet the requirement of the temperature measuring for wireless power transfer.

Based on the characteristics of infrared imaging, the algorithm of pseudo-color processing for infrared images is studied on the basis of independent research and development of infrared imaging system. A real-time pseudo-color processing algorithm based on FPGA is designed, software module by Verilog and the hardware platform are also introduced. In this method, three kinds of RGB color components are obtained by three kinds of independent transform, finally, the color images are synthesized. The algorithm has been applied to our self-designed infrared imaging system, results show that it is easy to implement and image enhancement effect is good.

The high diffraction efficiency of the convex blazed gratings cannot be realized in the broadband. Therefore, we have designed the convex dual-blazed grating to realize higher and uniform diffraction efficiency in the wavelength from 0.4 μm to 2.5 μm. The diffraction efficiency of the convex dual-blazed grating is investigated by using rigorous coupled wave analysis. The results show: when the two blaze angles of the convex dual-blazed grating, one within the range from 2.7 degree to 3.4 degree and the other one within the range from 8 degree to 9 degree respectively, the first-order diffraction efficiency is more than 25 percent at the visible-near infrared band. The convex dual-blazed grating with the period of 5μm in the center will be fabricated by holographic lithography-segmented ion beam etching in late 2017.

According to the environmental requirement of detectors, we studied the characteristics of Si and InGaAs detectors irradiated by the Cobalt60-γray with the total dose of 5krad, 10 krad, 20 krad, 30krad respectively. We measured the dark current and relative spectral responsivity by the Relative Responsivity Measurement Apparatus before and after irradiation. The results suggest that the characteristics of Silicon and InGaAs detectors don't change obviously after different total dose irradiation, both detectors can work in the space irradiation environment due to its stability and reliability.

The technique of spectral polarization detection is currently one of the important contents of the research at home and abroad. The measuring principle of mid-infrared hyperspectral polarization was introduced. The measuring system of mid-wave infrared hyperspectral polarization was set up. The measuring experiments of polarization characteristic of two coating materials at different temperatures were carried out. The effective experimental data was obtained and analysed. The results show that: as the temperature goes up, the radiance of coating material increase; the more the difference of temperature and emissivity is, the more the upgrade of radiance is; the upgrade of degree of polarization don’t occurs larger change as the change of the upgrade of radiance. This phenomenon provides a meaningful reference for the application of mid-wave infrared spectral polarization characteristic.

In this paper, we proposed a new infrared image detail enhancement approach. This approach could not only achieve the goal of enhancing the digital detail, but also make the processed image much closer to the real situation. Inspired by the joint-bilateral filter, two adjacent images were utilized to calculate the kernel functions in order to distinguish the detail information from the raw image. We also designed a new kernel function to modify the joint-bilateral filter and to eliminate the gradient reversal artifacts caused by the non-linear filtering. The new kernel is based on an adaptive emerge coefficient to realize the detail layer determination. The detail information was modified by the adaptive emerge coefficient along with two key parameters to realize the detail enhancement. Finally, we combined the processed detail layer with the base layer and rearrange the high dynamic image into monitor-suited low dynamic range to achieve better visual effect. Numerical calculation showed this new technology has the best value compare to the previous research in detail enhancement. Figures and data flowcharts were demonstrated in the paper.

Low Level Light (LLL) night vision technology is extensively applied in national defense and civil application fields. The digitization of LLL imaging is trend of light detection technology in the future. The corresponding modulation transfer function (MTF) and total system MTF model were established, base on the structure composition and operation principle. Simulation was carried out to analyze the performance of the MTF modern. Results indicate that the MCPCMOS better contrast of object. When the spatial frequency increasing, the MTF of MCP-CMOS downing faster than that of GaAs LLL image intensifier. The GaAs image intensifier shows an better image restoration capability and higher limiting resolution. The model and simulation results can provide a theoretical guidance for the fabrication and application of high imaging quality MCP-CMOS.

Apparent distance is a reflection of the performance of low-light night vision system, but also an important parameter indicator in the design stage of LLL night vision system. As the working environment is changing, it is difficult to accurately estimate the apparent distance. Except the parameters of the system itself and the series of parameters caused by the weather environment, the contrast of the target and background is also the important factor to affect performance of the system. In this paper, we use ICCD to test the contrast of target and background of several typical scenes in the use of low-light night vision system, and get the contrast of target and background, which is very important to the prediction of apparent distance.

The high-gain photomultiplier tube (PMT) is the most popular method to detect weak ultra-violet signals which attenuate quickly in atmosphere, although the vacuum tube makes it fragile and difficult to integrate. To overcome the disadvantage of PMT, an AlN/GaN periodically–stacked-structure (PSS) avalanche photodiode (APD) has been proposed, finally achieving good quality of high gain and low excessive noise. As there is a deep г valley only in the conduction band of both GaN and AlN, the electron transfers suffering less scattering and thus becomes easier to obtain the threshold of ionization impact. Because of unipolar ionization in the PSS APD, it works in linear mode. Four prototype devices of 5-period, 10-period, 15-period, and 20-period were fabricated to verify that the gain of APD increases exponentially with period number. And in 20-period device, a recorded high and stable gain of 104 was achieved under constant bias. In addition, it is proved both experimentally and theoretically, that temperature stability on gain is significantly improved in PSS APD. And it is found that the resonant enhancement in interfacial ionization may bring significant enhancement of electron ionization performance. To make further progress in PSS APD, the device structure is investigated by simulation. Both the gain and temperature stability are optimized alternatively by a proper design of periodical thickness and AlN layer occupancy.

Low level light(LLL) image contains rich information on environment details, but is easily affected by the weather. In the case of smoke, rain, cloud or fog, much target information will lose. Infrared image, which is from the radiation produced by the object itself, can be "active" to obtain the target information in the scene. However, the image contrast and resolution is bad, the ability of the acquisition of target details is very poor, and the imaging mode does not conform to the human visual habit. The fusion of LLL and infrared image can make up for the deficiency of each sensor and give play to the advantages of single sensor. At first, we show the hardware design of fusion circuit. Then, through the recognition probability calculation of the target(one person) and the background image(trees), we find that the trees detection probability of LLL image is higher than that of the infrared image, and the person detection probability of the infrared image is obviously higher than that of LLL image. The detection probability of fusion image for one person and trees is higher than that of single detector. Therefore, image fusion can significantly enlarge recognition probability and improve detection efficiency.

In this study, we investigate the fractal properties of optical turbulence profiles. Through rescaled range analysis, optical turbulence profiles roughly exhibit three different regimes. The effects of stratifications are the underlying mechanism contributing to this phenomenon. The results of detrended fluctuation analysis and multifractal detrended fluctuation analysis indicate that optical turbulence profiles have multifractal structure.

The flow field around a hemispherical/cylindrical structure at Mach number of Ma=0.4 is calculated, and the distributions of temporal root mean square value of velocity and density in the wake are presented. Further more, the optical path difference and aero-optical phase are calculated according to density field, and then the impact of the wake on adaptive optics systems with a point source and a plane-wave source beacon is studied respectively. It is found that there are plentiful turbulent structures in the wake, and the maximum values of the temporal root mean square of density and velocity both decrease 84% when the distance from the calculated position to the center of the structure varies from 0.43 m to 1.5 m. The spatial root mean square of optical path difference varies dramatically over time, and its time average gain two times while the angle of projection varies from 120°to 148°. The hemispherical/cylindrical wake has little impact on the adaptive optics system when the beacon is point source. While the wake has great impact when the beacon is plane-wave source, and the impact gets worse when the angle of projection gets larger. The Strehl ratio of the main laser decreases from 0.72 to 0.33 when the angle of projection increases from 120°to 148°.

We demonstrate a time-of-flight absolute distance measurement method based second harmonic generation using dual-comb with different repetition rates. A distance of about 8m is measured, compared with a laser absolute tracer, the maximum deviation is 19μm at 100ms acquisition time.

The classic modeling methods always take the vehicle hood temperature as a fixed value. However, the field test results show that the temperature distribution of the hood is obviously nonuniform while the engine works. Taking the actual structure of the vehicle and various factors into account, the temperature field distribution model of the vehicle hood is set up and its rationality is further verified, with the influence of the radiation angle coefficient being analyzed. Moreover, the temperature field model of the vehicle hood is simulated and verified. The results show that the model of the hood temperature field is consistent with the actual situation.

Aiming at the characteristics in HSI colour space of remote sensing images at different time in VR, a unified colour algorithm is proposed. First the method converted original image from RGB colour space to HSI colour space. Then, based on the invariance of the hue before and after the colour adjustment in the HSI colour space and the brightness translational features of the image after the colour adjustment, establish the linear model which satisfied these characteristics of the image. And then determine the range of the parameters in the model. Finally, according to the established colour adjustment model, the experimental verification is carried out. The experimental results show the proposed model can effectively recover the clear image, and the algorithm is faster. The experimental results show the proposed algorithm can effectively enhance the image clarity and can solve the pigment block problem well.

Recent years have shown that deep learning neural networks are a valuable tool in the field of computer vision. Deep learning method can be used in applications like remote sensing such as Land cover Classification, Detection of Vehicle in Satellite Images, Hyper spectral Image classification. This paper addresses the use of the deep learning artificial neural network in Satellite image segmentation. Image segmentation plays an important role in image processing. The hue of the remote sensing image often has a large hue difference, which will result in the poor display of the images in the VR environment. Image segmentation is a pre processing technique applied to the original images and splits the image into many parts which have different hue to unify the color. Several computational models based on supervised, unsupervised, parametric, probabilistic region based image segmentation techniques have been proposed. Recently, one of the machine learning technique known as, deep learning with convolution neural network has been widely used for development of efficient and automatic image segmentation models. In this paper, we focus on study of deep neural convolution network and its variants for automatic image segmentation rather than traditional image segmentation strategies.

By analyzing the image degradation mechanism in the Non-uniform path, the MTF equivalent principle of the turbid medium is used to obtain the fog weather modulation transfer function, and the spatial frequency domain filter is applied to the clear image to simulate the fog weather image blur effect, Under the conditions of the target scene simulation, and simulation results better than other low-pass filter.

Utilizing the quantized Huygens-Fresnel principle, we study the effects of anisotropic non-Kolmogorov turbulence on the average polarizability of quantization Bessel-Gaussian Schell-model (BGSM) photon beams. We find that the average polarizability has a weak dependence on the outer scale. By decreasing the source transverse coherent width, transmission distance and receiver aperture diameter, or increasing wavelength and photon number, we can improve the average polarizability. In addition, the average polarizability increases with increasing inner scale and anisotropic factor, or decreasing refractive-index structure parameter. This work reveals that we can utilize higher number of photons, lower source transverse coherent width and longer “window” wavelength to improve the performance of a polarizationencoded free-space quantum communication system.

The laser beam is attenuated, broadened, defocused and may even be deflected from its initial propagation direction as it propagates through the atmosphere. It leads to the decrease of the laser intensity of the receiving surface. Gauss beam is the fundamental components of all possible laser waveforms. Therefore, research on the transmission of the Gauss laser has far-reaching consequences in optical communication, weaponry, target designation, ranging, remote sensing and other applications that require transmission of laser beams through the atmosphere. In this paper, we propose a laboratory simulation method using multi-phase screen to calculate the effects of atmospheric turbulence. Theoretical analysis of Gauss laser transmission in the atmosphere is given. By calculating the propagation of the Gauss beam TEM00, the far field intensity and phase distribution is shown. By the given method, the optical setup is presented and used for optimizing the adaptive optics algorithm.

Superposition theory of the spiral harmonics is employed to numerical study the transmission property of the orbital angular momentum (OAM) mode of Gaussian beam induced by atmospheric turbulence. Results show that Gauss beam does not carry OAM at the source, but various OAM modes appear after affected by atmospheric turbulence. With the increase of atmospheric turbulence strength, the smaller order OAM modes appear firstly, followed by larger order OAM modes. The beam spreading of Gauss beams in the atmosphere enhance with the increasing topological charge of the OAM modes caused by atmospheric turbulence. The mode probability density of the OAM generated by atmospheric turbulence decreases, and peak position gradually deviate from the Gauss beam spot center with the increase of the topological charge. Our results may be useful for improving the performance of long distance laser digital spiral imaging system.

Temperature Water Vapor and Aerosols Raman Lidar has been designed for the measurement of atmospheric composition. In order to investigate characteristics of aerosol boundary layer (ABL) height in Beijing, the lidar system had been installed in the University of Chinese academy of sciences from November 2014 to January 2015 (40.41°N, 116.68°E). The data obtained by Raman lidar have been used to derive the ABL height (ABLH) based on the gradient method. A total of 15 days of haze, 27 days of pollution and 24 days of clean occurred through the entire period of observation. On haze, pollution and clean days, the average ABLH were 0.6~0.9 km, 0.9~1.3 km and 1~1.9 km, respectively. In contrast to clean days, haze days have lower ABLH, and gradient changes are faster. The measurement results show the height of ABL has a negative correlation with the concentration of surface PM. The rate of PM concentration variations increase gradually with the height of ABL in clean, pollution and haze days. the atmospheric temperature distribution is relatively stable in two hours. Temperature from 2 to 3 km altitude tends to increase gradually for the observation period.

GF-2 remote sensing products have been widely used in many fields for its high-quality information, which provides technical support for the the macroeconomic decisions. Atmospheric correction is the necessary part in the data preprocessing of the quantitative high resolution remote sensing, which can eliminate the signal interference in the radiation path caused by atmospheric scattering and absorption, and reducting apparent reflectance into real reflectance of the surface targets. Aiming at the problem that current research lack of atmospheric date which are synchronization and region matching of the surface observation image, this research utilize the MODIS Level 1B synchronous data to simulate synchronized atmospheric condition, and write programs to implementation process of aerosol retrieval and atmospheric correction, then generate a lookup table of the remote sensing image based on the radioactive transfer model of 6S (second simulation of a satellite signal in the solar spectrum) to correct the atmospheric effect of multispectral image from GF-2 satellite PMS-1 payload. According to the correction results, this paper analyzes the pixel histogram of the reflectance spectrum of the 4 spectral bands of PMS-1, and evaluates the correction results of different spectral bands. Then conducted a comparison experiment on the same GF-2 image based on the QUAC. According to the different targets respectively statistics the average value of NDVI, implement a comparative study of NDVI from two different results. The degree of influence was discussed by whether to adopt synchronous atmospheric date. The study shows that the result of the synchronous atmospheric parameters have significantly improved the quantitative application of the GF-2 remote sensing data.

The simulation of aerial flying targets is widely needed in many fields. This paper proposes a physically based method for optical simulation of flying targets. In the first step, three-dimensional target models are built and the motion speed and direction are defined. Next, the material of the outward appearance of a target is also simulated. Then the illumination conditions are defined. After all definitions are given, all settings are encoded in a description file. Finally, simulated results are generated by Monte Carlo ray tracing in a physically based renderer. Experiments show that this method is able to simulate materials, lighting and motion blur for flying targets, and it can generate convincing and highquality simulation results.

PM_2.5 and PM₁₀ are very important indexes reflecting the air quality in atmospheric environment monitoring. Based on Mie angular scattering theory, a system measuring particulates diameter and concentration of PM_2.5 and PM₁₀ was designed, which used optical fiber as transmission medium. Theoretical deduction and Matlab program simulation were presented to illustrate the basic principle of Mie angular scattering. The influences of laser wavelength, detection angle and other parameters on the measurement accuracy were discussed in detail. It had been found that the measurement results had multi-valued problem when the measurement angle range was too small. However, this problem was eliminated obviously when the angle range is greater than 25 degrees.

For a better understanding and forecasting of the universe, the high resolution observations are needed. The largeaperture telescope is an integrated success with a combination of material, mechanics, optics and electronics. The telescope is a classic Cassegrain configuration with open structure, alt-azimuth mount, and retractable dome. The instrumentation has a rotating mass of approximately 52 tons and stands over 9 m tall. The 3-m aperture primary mirror is a honeycomb lightweighted mirror with fused silica material and active cooling. The paper will address preliminary design and development of the telescope mount structure, axes drive system, encoder mount and primary mirror system. The structure must have the best performance of stiffness and stability to demand an acceptable image quality. As the largest optical element of the telescope, primary mirror must be well controlled and protected both during operational and non-operational periods. An active cooling system of primary mirror is provided by a flushing subsystem at the front side and sucking subsystem on the central hole to keep the temperature of the facesheet close to that of ambient air. A two-layer mirror cover mounted on the elevation ring is proposed to protect the optical elements and inner beam tube from dust, dirt and debris. Furthermore, the latest plans for future upgrades will be also described.

This paper mainly introduces the research progress of free space coherent optical communication in Xi'an University of Technology. In recent years, the research on the outer modulation technology of the laser, free-space-to-fiber coupling technique, the design of transmitting and receiving optical antenna, adaptive optical technology with or without wave-front sensor, automatic polarization control technology, frequency stabilization technology, heterodyne detection technology and high speed signal processing technology. Based on the above related research, the digital signal modulation, transmission, detection and data recovery are realized by the heterodyne detection technology in the free space optical communication system, and finally the function of smooth viewing high-definition video is realized.